The 1973 MUDDLE; TS MIDAS binary has these four instruction aliases with
SI at the end (and they weren't used in the 1973 Muddle at all). All
later versions of MIDAS use RI names, as does more recent Muddle source,
so this must have been patched in later.
Older versions of MIDAS expect you to type a command at them, which
makes them hard to automate with :x or XFILEs. This patch backports the
JCLINI code from later versions of MIDAS, which pre-stuffs the command
buffer with the JCL string if available.
This was edited from later versions of the source to match MUDDLE; TS
MIDAS circa 1973, which was built with MOBY==0. The program itself dates
from no later than 1971. Comments, and results when built with other
options, are probably not historically accurate.
MIDAS 73 is useful because 74 and all later versions have completely
rewritten code for relocatable output (and for IO), and they don't
support some of STINK's features correctly (or at all). A ported version
of MIDAS 73 was still being used to build Muddle in the 1980s, going by
<mdl.int>midas.exe.5.